Initial phases of the project involve investigating the relationship between laterality of left and right hemisphere brain function and the decline of verbal and nonverbal information processing with age. Young, middle aged and elderly men and women are asked to make decisions concerning verbal and nonverbal stimuli, which are presented in the auditory and visual modes. Time required to make a decision and the number of errors made in responding are the variables measured. Continuing phases of the project involve the relationship of cardiovascular disease to laterality of brain function. Probability learning, strategy changes and perceptual "space" are also being investigated as secondary phases of the project. BIBLIOGRAPHIC REFERENCE: Winn, F.J. & Elias, J.W. Total time principle as a substitute for the pacing variable in paired-associate studies with the aged. J. Exp. Aging Research, In press, 1976.